The preparation and measurement of antibodies with a high degree of specificity for human malignant melanoma tumor-associated antigens is planned using a combination of recently developed procedures. These include a) induction of antibodies to tumor cells in rabbits and non-human primates, using non-immunogenic newly developed potent adjuvants, b) the use of cellular immunoadsorbents consisting of well characterized and formalin-treated cultured tumor and normal cells coupled to diethylaminoethyl cellulose and c) the use of radiolabeled Staphylococcal Protein A to detect and quantitate antibodies bound to tumor and normal cell surfaces. Monoclonal antibodies to tumor cells will also be produced. Their specificity and their binding characteristics will be compared to those obtained from cellular immunoadsorbents. We will employ a variety of established and characterized tissue-cultured tumor and normal lymphoid cell lines. Of special interest will be the availability of paired tumor and autochthonous lymphoid cell lines grown under identical conditions of tissue culture. Advantage will be taken of the combined facilities of an experienced and active tissue culture laboratory and a tumor immunology group that has experience in measuring the direct and primary interactions between antigens and antibodies. After specific antisera are produced and characterized they will be used to isolate tumor-associated antigens. It will be possible to compare antigens of allogeneic tumors of the same histologic type. Purified antibodies and antigens may be of value for immunodiagnostic and possibly for immunotherapeutic purposes. Characterized antigens will be used to develop new radioimmunoassays and to induce antisera with high specificity. Reactions between antisera and cell surface antigens will be studied by a variety of techniques including SDS-polyacrylamide electrophoresis of immunoprecipitates made of radiolabeled tumor cell surfaces and selected antisera.